Stress state mediation between environmental variables and performance: the case of noise and vigilance

The ANT Executive Control Index: No Evidence for Temporal Decrement

OBJECTIVE

This study tested whether indices of executive control, alertness, and orienting measured with Attention Network Test (ANT) are vulnerable to temporal decrement in performance.

BACKGROUND

Developing the resource theory of sustained attention requires identifying neurocognitive processes vulnerable to decrement. Executive control processes may be prone to impairment in fatigue states. Such processes are also highlighted in alternative theories. Determining the role of executive control in vigilance can both advance theory and contribute to practical countermeasures for decrement in human factors contexts.

METHOD

In Study 1, 80 participants performed the standard ANT for an extended duration of about 55 to 60 min. Study 2 (160 participants) introduced manipulations of trial blocking and stimulus degradation intended to increase resource depletion. Reaction time and accuracy measures were analyzed. Subjective stress and workload were assessed in both studies.

RESULTS

In both studies, the ANT induced levels of subjective workload and task disengagement consistent with previous sustained attention studies. No systematic decrement in any performance measure was observed.

CONCLUSION

Executive control assessed by the ANT is not highly vulnerable to temporal decrement, even when task demands are elevated. Future work should differentiate executive control processes; proactive control may be more implicated in sustained attention decrement than in reactive control.

APPLICATION

Designing systems and interfaces to reduce executive control demands may be generally beneficial but will not directly mitigate temporal performance decrement. Enhancing design guidelines and neuroergonomic methods for monitoring operator attention requires further work to identify key neurocognitive processes for decrement.

The influence of classroom seating arrangement on children's cognitive processes in primary school: the role of individual variables

To date, despite the great debate regarding the best seating arrangement for learning in classrooms, no empirical studies have examined the direct effects of different seating arrangements on children’s cognitive processes. This is particularly important nowadays that the COVID-19 measures include maintaining distance in the classroom. Aim of this study was experimentally investigating the effect of changing the seating arrangement (clusters vs. single desks), on logical reasoning, creativity and theory of mind, in children attending primary school. Furthermore, some individual characteristics (e.g., gender, loneliness, popularity) were analysed as potential moderators. Results on 77 participants showed that, when children were seated in single desks, their score in logical reasoning was globally higher. Furthermore, when seated in single desks, girls showed a better performance in the theory of mind, and lonelier children performed better in theory of mind and creativity. This on field experimental study suggests the importance of considering both the nature of the task and children’s individual characteristics when deciding on a seating arrangement in the classroom.

The Interaction Between Physical and Psychosocial Stressors

Do physical and psychosocial stressors interact to increase stress in ways not explainable by the stressors alone? A preliminary study compared participants' stress response while subjected to a physical stressor (reduced or full physical load) and a predetermined social stressor (confronted by calm or aggressive behavior). Salivary cortisol samples measured endocrine stress. Heart rate variability (HRV) and electrodermal activity (EDA) measured autonomic stress. Perceived stress was measured via discomfort and stress state surveys. Participants with a heavier load reported increased distress and discomfort. Encountering an aggressive individual increased endocrine stress, distress levels, and perceived discomfort. Higher autonomic stress and discomfort were found in participants with heavier physical load and aggressive individuals. The results suggest a relationship where physical load increases the stressfulness of aggressive behavior in ways not explainable by the effects of the stressors alone. Future research is needed to confirm this investigation's findings.

Understanding individualistic response patterns when assessing expert operators on nuclear power plant control tasks

We evaluated the performance of three highly practiced participants on three task types that comprised a simulated nuclear power plant control operation. Multiple subjective, physiological, and objective performance measures were collected on these three highly-practiced individuals. Results indicated ceiling effects in terms of performance accuracy, yet each individual adopted a unique response strategy across the respective sub-tasks. Their maximised accuracy was achieved at the expense of longer response times across differing sub-tasks. The measures which proved diagnostic and predictive of performance capacity were explored. The current conclusion presents us with an invidious problem in that performance and workload associations, insensitivities, and dissociations may be unique to each individual operator, and may well depend also upon the overall task in context. Such findings push our science away from seeking nomothetic assertions and toward individuated concerns. In consequence, the age of the idiographic may well be upon us. Practitioner summary: The importance and relevance of nuclear power control is self-evident. Concerns here have centred around the safety of the technology and its operators. Our work informs practitioners in this industry, and in Ergonomics in general, of the response of highly trained individuals in these safety-critical, operational domains. We show that even experts engage in personal and individual strategies, an observation critical to the assessment of this specific workplace, and potentially all others. Abbreviations: NPP: nuclear power plant; ROs: reactor operators; MCR: main control room; LOA: levels of automation; EOP: emergency operating procedure; OP: operating procedures; ISA: instantaneous self-assessment; DSSQ: Dundee stres state questionnaire.

Brain Connectivity Analysis Under Semantic Vigilance and Enhanced Mental States

In this paper, we present a method to quantify the coupling between brain regions under vigilance and enhanced mental states by utilizing partial directed coherence (PDC) and graph theory analysis (GTA). The vigilance state is induced using a modified version of stroop color-word task (SCWT) while the enhancement state is based on audio stimulation with a pure tone of 250 Hz. The audio stimulation was presented to the right and left ears simultaneously for one-hour while participants perform the SCWT. The quantification of mental states was performed by means of statistical analysis of indexes based on GTA, behavioral responses of time-on-task (TOT), and Brunel Mood Scale (BRMUS). The results show that PDC is very sensitive to vigilance decrement and shows that the brain connectivity network is significantly reduced with increasing TOT, p < 0.05. Meanwhile, during the enhanced state, the connectivity network maintains high connectivity as time passes and shows significant improvements compared to vigilance state. The audio stimulation enhances the connectivity network over the frontal and parietal regions and the right hemisphere. The increase in the connectivity network correlates with individual differences in the magnitude of the vigilance enhancement assessed by response time to stimuli. Our results provide evidence for enhancement of cognitive processing efficiency with audio stimulation. The BRMUS was used to evaluate the emotional states of vigilance task before and after using the audio stimulation. BRMUS factors, such as fatigue, depression, and anger, significantly decrease in the enhancement group compared to vigilance group. On the other hand, happy and calmness factors increased with audio stimulation, p < 0.05.

Task Engagement and the Vigilance Decrement Revisited: Expanding Upon the Work of Joel S. Warm Using a Semantic Vigilance Paradigm

OBJECTIVE

The goal of the present study is twofold: (1) demonstrate the importance of measuring and understanding the relationship between task engagement and vigilance performance, and (2) celebrate the work of Joel S. Warm and expand upon his previous research in two semantic vigilance paradigms.

BACKGROUND

The importance of measuring task engagement in cognitive and sensory vigilance tasks has been well documented. But to date, our understanding of the effects of task engagement on semantic vigilance performance is limited.

METHOD

Seventy-three participants completed either a standard semantic vigilance task or a lure semantic vigilance task. Participants also completed subjective measures of workload and stress.

RESULTS

The results indicated that changes in task engagement are associated with correct detection performance. Changes in task engagement may be related to individual differences in the distress associated with performing semantic vigilance tasks.

CONCLUSION

In line with the work of Warm and his colleagues (Dember, Warm, Bowers, & Lanzetta, 1984), participants who reported increased task engagement after the vigil outperformed their peers who noted decreased task engagement upon conclusion of the task. Participants reporting increases in engagement with the semantic vigilance tasks also reported significantly greater distress pretask, but not posttask. Instead, increases in postvigil distress were driven by the task to which participants were assigned, not task engagement.

APPLICATION

The present study has several implications for applied settings that involve long duration semantic processing or semantic target identification. Such real-world tasks include aviation, cyber threat detection and analysis, driving, and reading.

Vigilance Tasks: Unpleasant, Mentally Demanding, and Stressful Even When Time Flies

OBJECTIVE

To determine whether perceived time progression (PTP) moderates participants' negative reactions to vigilance tasks.

BACKGROUND

Vigilance tasks are rated by participants to be unenjoyable and as having high levels of workload and stress. Based on the adage, "You are having fun when time flies," we tested the possibility that accelerating PTP might reduce these negative experiences.

METHOD

Two studies were performed, involving a long 30-min and a short 12-min vigil. We manipulated participants' PTP by creating a mismatch between their expectations about how long they would perform the task and the actual time that they were engaged.

RESULTS

PTP was significantly faster for participants who were led to expect that the vigilance task would last longer than it did relative to those led to expect that task duration would be shorter than it actually was and for controls for whom task duration was equal to the expected duration. However, accelerating PTP had no effect in either experiment on undesirable reactions to the vigilance tasks. Participants uniformly rated both tasks as unenjoyable, as having a high level of workload, and as stressful. Apparently, vigilance isn't fun even when time flies.

CONCLUSION

Our findings greatly underscore the depth to which negative subjective reactions are embedded in the nature of vigilance tasks and therefore that these tasks can have potentially serious costs to participants in terms of health, safety, and productivity.

APPLICATION

These costs must be considered at the operational level.

Socially alerted cognition evoked by a confederate's mere presence: analysis of reaction-time distributions and delta plots

We examined aspects of social alerting as induced through the presence of an attentive but non-evaluative confederate on mental efficiency. To this end, individuals were administered with a chained mental-arithmetic task (levels: low vs. high demand) in two contextual conditions (levels: alone vs. presence). In addition, we examined self-report measures of subjective state for purposes of control. As a result, the presence (vs. alone) condition improved (not hampered) processing speed (while error rate remained low overall), and this effect was differentially more pronounced for high (vs. low) demand. Reaction-time distributional analyses revealed that improvements in average performance actually originated from a selective speeding-up in the slower percentiles, indicating that social alerting promotes stability of information-processing throughput. These results challenge prevalent theoretical notions of mere-presence effects as individuals became consistently faster and less vulnerable to commit attention failure. Our findings indicate that social presence promotes not only processing speed but volitional steadiness.

Using Situation Awareness and Workload to Predict Performance in Submarine Track Management: A Multilevel Approach

OBJECTIVE

Examine the extent to which subjective workload and situation awareness (SA) can predict variance in performance at the between- and within-person levels of analysis in a simulated submarine track management task.

BACKGROUND

SA and workload are crucial constructs in human factors that are conceptualized as states that change within individuals over time. Thus, a change in an individual's subjective workload or SA over the course of performing a task should be predictive of their subsequent performance (within-person effects). However, there is little empirical evidence for this.

METHOD

Participants monitored displays to track the behaviors of contacts in relationship to their own ship (Ownship) and landmarks. The Situational Awareness Global Assessment Technique measured SA, and the Air Traffic Workload Input Technique measured subjective workload.

RESULTS

When a participant's subjective workload rating increased, their subsequent performance decreased, but there was no evidence for within-person effects of SA on performance. We replicated prior between-person level effects of SA; participants with higher SA performed better than those with lower SA.

CONCLUSION

Change in an individual's subjective workload rating (but not SA) was predictive of their subsequent performance. Because an increase in SA should increase the extent to which operators hold the knowledge required to perform subsequent tasks, further research is required to examine SA effects on performance at the within-person level.

APPLICATION

Adapting automation is more likely to produce optimal outcomes if based on measurement of operator states that predict future task performance, such as workload.

Examining social facilitation in vigilance: a hit and a miss

Vigilance is the ability of an observer to maintain attention for extended periods of time; however, performance tends to decline with time on watch, a pattern referred to as the vigilance decrement. Previous research has focused on factors that attenuate the decrement; however, one factor rarely studied is the effect of social facilitation. The purpose for the present investigation was to determine how different types of social presence affected the performance, workload and stress of vigilance. It was hypothesised that the presence of a supervisory figure would increase overall performance, but may occur at the cost of increased workload and stress. Results indicated that the per cent of false alarm and response times decreased in the presence of a supervisory figure. Using social facilitation in vigilance tasks may thus have positive, as well as, negative effects depending on the dependent measure of interest and the role of the observer. Practitioner Summary: Social facilitation has rarely been examined in the context of vigilance, even though it may improve performance. Vigilance task performance was examined under social presence. The results of the present study indicated that false alarms and response times decreased in the social presence of a supervisory figure, thus improving performance.

Task Engagement and Attentional Resources

OBJECTIVE

Two studies tested multivariate models of relationships between subjective task engagement and vigilance. The second study included a stress factor (cold infection). Modeling tested relationships between latent factors for task engagement and vigilance, and the role of engagement in mediating effects of cold infection.

BACKGROUND

Raja Parasuraman's research on vigilance identified several key issues, including the roles of task factors, arousal processes, and individual differences, within the framework of resource theory. Task engagement is positively correlated with performance on various attentional tasks and may serve as a marker for resource availability.

METHOD

In the first study, 229 participants performed simultaneous and successive vigilance tasks. In the second study, 204 participants performed a vigilance task and a variable-foreperiod simple reaction-time task on two separate days. On the second day, 96 participants performed while infected with a naturally occurring common cold. Task engagement was assessed in both studies.

RESULTS

In both studies, vigilance decrement in hit rate was observed, and task performance led to loss of task engagement. Cold infection also depressed both vigilance and engagement. Fitting structural equation models indicated that simultaneous and successive tasks should be represented by separate latent factors (Study 1), and task engagement fully mediated the impact of cold infection on vigilance but not reaction time (Study 2).

CONCLUSIONS

Modeling individual differences in task engagement elucidates the role of resources in vigilance and underscores the relevance of Parasuraman's vision of the field.

APPLICATION

Assessment of task engagement may support diagnostic monitoring of operators performing tasks requiring vigilance.

An individual differences approach to multiple-target visual search errors: How search errors relate to different characteristics of attention

A persistent problem in visual search is that searchers are more likely to miss a target if they have already found another in the same display. This phenomenon, the Subsequent Search Miss (SSM) effect, has remained despite being a known issue for decades. Increasingly, evidence supports a resource depletion account of SSM errors-a previously detected target consumes attentional resources leaving fewer resources available for the processing of a second target. However, "attention" is broadly defined and is composed of many different characteristics, leaving considerable uncertainty about how attention affects second-target detection. The goal of the current study was to identify which attentional characteristics (i.e., selection, limited capacity, modulation, and vigilance) related to second-target misses. The current study compared second-target misses to an attentional blink task and a vigilance task, which both have established measures that were used to operationally define each of four attentional characteristics. Second-target misses in the multiple-target search were correlated with (1) a measure of the time it took for the second target to recovery from the blink in the attentional blink task (i.e., modulation), and (2) target sensitivity (d') in the vigilance task (i.e., vigilance). Participants with longer recovery and poorer vigilance had more second-target misses in the multiple-target visual search task. The results add further support to a resource depletion account of SSM errors and highlight that worse modulation and poor vigilance reflect a deficit in attentional resources that can account for SSM errors.

Positive post-disaster images: A daydream machine?

This study explores the impact of post-earthquake images inserted in a vigilance task, in terms of performance, self-reports of task-focus, and cerebral activity using functional near-infrared spectroscopy (fNIRS). Vigilance tasks present a sequence of stimuli in which only a few are pre-designated critical or target stimuli requiring an overt response from the participant. Seventy-one residents participated (51 women, 20 men) by taking part in a vigilance task with task-irrelevant images inserted in the sequence. There were three conditions consisting positive (emotive inducing), negative (emotive inducing), and control (devoid of meaning) images embedded in the vigilance task to assess possible impacts on vigilance performance. The images were obtained through crowdsourcing and represented parts of the city 3-4 years post-earthquake. Task performance was assessed with signal detection theory metrics of sensitivity A' and bias β''. This enables the separation of an individual's ability to accurately discriminate critical signals from non-critical stimuli (sensitivity) and shifts in their willingness to respond to any stimuli whether critical or not (bias). Individuals viewing the positive images, relating to progress, rebuild, or aesthetic aspects within the city, had a more conservative response bias (they responded less to both rare critical and distractor stimuli) than those in the other conditions. These individuals also reported lower task-focus, as would be expected. However, contrary to expectations, indicators of cerebral activity (fNIRS) did not differ significantly between the experimental groups. These results, when combined, suggest that mind wandering events may be being generated when exposed to positive post-earthquake images.

Multidimensional Profiling of Task Stress States for Human Factors: A Brief Review

OBJECTIVE

This article advocates multidimensional assessment of task stress in human factors and reviews the use of the Dundee Stress State Questionnaire (DSSQ) for evaluation of systems and operators.

BACKGROUND

Contemporary stress research has progressed from an exclusive focus on environmental stressors to transactional perspectives on the stress process. Performance impacts of stress reflect the operator's dynamic attempts to understand and cope with task demands. Multidimensional stress assessments are necessary to gauge the different forms of system-operator interaction.

METHOD

This review discusses the theoretical and practical use of the DSSQ in evaluating multidimensional patterns of stress response. It presents psychometric evidence for the multidimensional perspective and illustrative profiles of subjective state response to task stressors and environments. Evidence is also presented on stress state correlations with related variables, including personality, stress process measures, psychophysiological response, and objective task performance.

RESULTS

Evidence supports the validity of the DSSQ as a task stress measure. Studies of various simulated environments show that different tasks elicit different profiles of stress state response. Operator characteristics such as resilience predict individual differences in state response to stressors. Structural equation modeling may be used to understand performance impacts of stress states.

CONCLUSION

Multidimensional assessment affords insight into the stress process in a variety of human factors contexts. Integrating subjective and psychophysiological assessment is a priority for future research.

APPLICATION

Stress state measurement contributes to evaluating system design, countermeasures to stress and fatigue, and performance vulnerabilities. It may also support personnel selection and diagnostic monitoring of operators.

The therapeutic impacts of environmental design interventions on wellness in clinical settings: A narrative review

PURPOSE

The aim of this review is to document the role of physical environmental factors in clinical environments and their impact on patients and staff wellness with a particular focus on physical and mental healthcare.

METHODS

Data sources comprised relevant English language articles and the results of literature search of ISI Web of Knowledge, PubMed, Scopus, ProQuest Central, MEDLINE, and Google.

RESULTS

Incorporating physical environmental factors into hospital design can facilitate better user satisfaction, efficiency and organisational outcomes. Many of the design interventions convey positive distractions for patients and staff, in terms of views of pleasant outside vistas, soothing sound, artwork and music.

CONCLUSIONS

Well-designed physical settings play an important role in the healing process of patients in health care facilities. The challenge then is to fully understand that role in the ecological context of health care. Other contributors are possible and should be explored in further research.

Short Stress State Questionnaire

Conscious appraisals of stress, or stress states, are an important aspect of human performance. This article presents evidence supporting the validity and measurement characteristics of a short multidimensional self-report measure of stress state, the Short Stress State Questionnaire (SSSQ; Helton, 2004 ). The SSSQ measures task engagement, distress, and worry. A confirmatory factor analysis of the SSSQ using data pooled from multiple samples suggests the SSSQ does have a three factor structure and post-task changes are not due to changes in factor structure, but to mean level changes (state changes). In addition, the SSSQ demonstrates sensitivity to task stressors in line with hypotheses. Different task conditions elicited unique patterns of stress state on the three factors of the SSSQ in line with prior predictions. The 24-item SSSQ is a valid measure of stress state which may be useful to researchers interested in conscious appraisals of task-related stress.

Effect of Noise Intensity and Illumination Intensity on Visual Performance

The results of Experiment 1 indicated that noise and illumination intensity have a significant effect on character identification performance, which was better at 30 dBA than at 60 and 90 dBA, and better at 500 and 800 lux than at 200 lux. However, the interaction of noise and illumination intensity did not significantly affect visual performance. The results of Experiment 2 indicated that noise and illumination intensity also had a significant effect on reading comprehension performance, which was better at 30 dBA than at 60 and 90 dBA, and better at 500 lux than at 200 and 800 lux. Furthermore, reading comprehension performance was better at 500 lux lighting and 30 dBA noise than with 800 lux and 90 dBA. High noise intensity impaired visual performance, and visual performance at normal illumination intensity was better than at other illumination intensities. The interaction of noise and illumination had a significant effect on reading comprehension. These results indicate that noise intensity lower than 30 dBA and illumination intensity approximately 500 lux might be the optimal conditions for visual work.

Vigilance on the move: video game-based measurement of sustained attention

Vigilance represents the capacity to sustain attention to any environmental source of information over prolonged periods on watch. Most stimuli used in vigilance research over the previous six decades have been relatively simple and often purport to represent important aspects of detection and discrimination tasks in real-world settings. Such displays are most frequently composed of single stimulus presentations in discrete trials against a uniform, often uncluttered background. The present experiment establishes a dynamic, first-person perspective vigilance task in motion using a video-game environment. 'Vigilance on the move' is thus a new paradigm for the study of sustained attention. We conclude that the stress of vigilance extends to the new paradigm, but whether the performance decrement emerges depends upon specific task parameters. The development of the task, the issues to be resolved and the pattern of performance, perceived workload and stress associated with performing such dynamic vigilance are reported.

PRACTITIONER SUMMARY

The present experiment establishes a dynamic, first-person perspective movement-based vigilance task using a video-game environment. 'Vigilance on the move' is thus a new paradigm for the evaluation of sustained attention in operational environments in which individuals move as they monitor their environment. Issues addressed in task development are described.

Predicting battlefield vigilance: a multivariate approach to assessment of attentional resources

Technological innovation increasingly requires operators in various applied settings to maintain vigilance for extended periods. However, standard psychometric tests typically predict less than 10% of performance variance. The present study (N = 462) aimed to apply the resource theory of sustained attention to construct a multivariate test battery for predicting battlefield vigilance. The battery included cognitive ability tests, a high-workload short vigilance task and subjective measures of stress response. Four versions of a 60- min simulated military battlefield monitoring task were constructed to represent different operational requirements. The test battery predicted 24-44% of criterion variance, depending on task version, suggesting that it may identify vigilant operators in military and other applied contexts. A multiple-groups path analysis showed that relationships between ability and vigilance were moderated by working memory demands. Findings are consistent with a diffuse theoretical concept of 'resources' in which performance energisation depends on multiple, loosely coupled processes.

Measuring workload in collaborative contexts: trait versus state perspectives

OBJECTIVE

In the present study, we explored the state versus trait aspects of measures of task and team workload in a disaster simulation.

BACKGROUND

There is often a need to assess workload in both individual and collaborative settings. Researchers in this field often use the NASATask Load Index (NASA-TLX) as a global measure of workload by aggregating the NASA-TLX's component items. Using this practice, one may overlook the distinction between traits and states.

METHOD

Fifteen dyadic teams (11 inexperienced, 4 experienced) completed five sessions of a tsunami disaster simulator. After every session, individuals completed a modified version of the NASA-TLX that included team workload measures.We then examined the workload items by using a between-subjects and within-subjects perspective.

RESULTS

Between-subjects and within-subjects correlations among the items indicated the workload items are more independent within subjects (as states) than between subjects (as traits). Correlations between the workload items and simulation performance were also different at the trait and state levels.

CONCLUSION

Workload may behave differently at trait (between-subjects) and state (within-subjects) levels.

APPLICATION

Researchers interested in workload measurement as a state should take a within-subjects perspective in their analyses.

Energetic arousal and language: predictions from the computational theory of quantifiers processing

OBJECTIVE

The author examines the relationship between energetic arousal (EA) and the processing of sentences containing natural-language quantifiers.

BACKGROUND

Previous studies and theories have shown that energy may differentially affect various cognitive functions. Recent investigations devoted to quantifiers strongly support the theory that various types of quantifiers involve different cognitive functions in the sentence-picture verification task.

METHOD

In the present study, 201 students were presented with a sentence-picture verification task consisting of simple propositions containing a quantifier that referred to the color of a car on display. Color pictures of cars accompanied the propositions. In addition, the level of participants' EA was measured before and after the verification task.

RESULTS

It was found that EA and performance on proportional quantifiers (e.g., "More than half of the cars are red") are in an inverted U-shaped relationship.

CONCLUSION

This result may be explained by the fact that proportional sentences engage working memory to a high degree, and previous models of EA-cognition associations have been based on the assumption that tasks that require parallel attentional and memory processes are best performed when energy is moderate.

APPLICATION

The research described in the present article has several applications, as it shows the optimal human conditions for verbal comprehension. For instance, it may be important in workplace design to control the level of arousal experienced by office staff when work is mostly related to the processing of complex texts. Energy level may be influenced by many factors, such as noise, time of day, or thermal conditions.

The Effect of Stress on Cognitive Structuring

In this article, we outline a model of the factors involved in the relationship between stress and cognitive structuring. More specifically, we propose that the desire for certainty, the need for cognitive structure, and perceived efficacy at satisfying one’s epistemic needs intervene in the effect exerted by stress on cognitive structuring. We further suggest expanding the model to account for aspects of general information processing and to encompass the effect of various trait-like characteristics on the cognitive response to stress. We also offer an account of the possible effects of extreme stress on the model’s components.

Natural scene stimuli and lapses of sustained attention

We conducted two experiments using naturalistic scene stimuli to test the resource theory and mindlessness theory of sustained attention. In experiment 1, 28 participants completed a traditional formatted vigilance task consisting of non-repeating forest or urban picture stimuli as target stimuli. Participants filled out pre- and post-task assessments of arousal and conscious thoughts. There was still a vigilance decrement, despite non-repetitive, natural target stimuli. Participants found the task demanding and were actively engaged in the task. In experiment 2, 25 participants completed a Sustained Attention to Response Task (SART) using the stimuli from experiment 1. Participants performed significantly worse on this SART than either brain injury patients or controls performing equivalent numeric stimuli SARTs have in previous studies. Participants thought the task was demanding and they were actively engaged with the task. Overall, the results of both studies support a resource theory of sustained attention lapses, not a mindlessness theory.

Spatial and temporal task characteristics as stress: a test of the dynamic adaptability theory of stress, workload, and performance

The goal for this study was to test assertions of the dynamic adaptability theory of stress, which proposes two fundamental task dimensions, information rate (temporal properties of a task) and information structure (spatial properties of a task). The theory predicts adaptive stability across stress magnitudes, with progressive and precipitous changes in adaptive response manifesting first as increases in perceived workload and stress and then as performance failure. Information structure was manipulated by varying the number of displays to be monitored (1, 2, 4 or 8 displays). Information rate was manipulated by varying stimulus presentation rate (8, 12, 16, or 20 events/min). A signal detection task was used in which critical signals were pairs of digits that differed by 0 or 1. Performance accuracy declined and workload and stress increased as a function of increased task demand, with a precipitous decline in accuracy at the highest demand levels. However, the form of performance change as well as the pattern of relationships between speed and accuracy and between performance and workload/stress indicates that some aspects of the theory need revision. Implications of the results for the theory and for future research are discussed.

The effects of emotional stimuli on target detection: indirect and direct resource costs

The present study was designed to explore the performance costs of negative emotional stimuli in a vigilance task. Forty participants (20 women) performed a vigilance task in two conditions: one with task-irrelevant negative-arousing pictures and one with task-irrelevant neutral pictures. In addition to performance, we measured subjective state (energetic arousal, tense arousal, task-related and task-unrelated thoughts) and frontal cerebral activity with near infrared spectroscopy. Overall performance in the negative picture condition was lower than in the neutral picture condition and the negative picture condition had elevated levels of energetic arousal, tense arousal and task-related thoughts. Moreover, there was a significant relationship between the impact of the negative pictures on tense arousal and task-related thoughts and the impact of the negative pictures on performance (in comparison to the neutral picture stimuli task). These results provide support for indirect cost models of negative emotional stimuli on target detection performance.

The effects of arousing negative and neutral picture stimuli on target detection in a vigilance task

OBJECTIVES

The present study was designed to explore whether target detection in a vigilance task is influenced by task-irrelevant negative emotional and neutral picture stimuli and to test predictions derived from the boredom-mindlessness versus resource depletion accounts of vigilance performance.

BACKGROUND

Previous research indicates that emotional stimuli can capture spatial attention. Research on the effect of negative emotional and neutral visual stimuli on temporal aspects of attention has not, however, been researched in detail.

METHOD

For this study, 51 participants (15 men and 36 women) were assigned at random to one of three vigilance conditions: a visual vigil with task-irrelevant negative-arousing pictures, a visual vigil with task-irrelevant neutral pictures, or a no-picture visual vigil control. Vigilance performance was assessed in all conditions.

RESULTS

Overall performance efficiency was negatively influenced by the negative-arousing pictures and was interpreted to favor resource depletion to boredom-mindlessness accounts of vigilance performance.

CONCLUSION

Task-unrelated negative emotional stimuli appear to impair absolute levels of target detections in a vigilance task.

APPLICATION

In monitoring settings where negative emotional stimuli are present, the intrusion of negative emotional stimuli should be mitigated via alterations in the system design, or if this is implausible, the monitors may need additional stress coping and emotional resilience training.

Assessing air medical crew real-time readiness to perform critical tasks

BACKGROUND

Air medical transport has had problems with its safety record, attributed in part to human error. Flight crew members (FCMs) must be able to focus on critical safety tasks in the context of a stressful environment. Flight crew members' cognitive readiness (CR) to perform their jobs may be affected by sleep deprivation, personal problems, high workload, and use of alcohol and drugs.

OBJECTIVE

The current study investigated the feasibility of using a computer-based cognitive task to assess FCMs' readiness to perform their job.

METHODS

The FCMs completed a short questionnaire to evaluate their physiologic and psychological state at the beginning and end of each shift. The FCMs then performed 3 minutes of a computer-based cognitive task called synthetic work environment (SYNWIN test battery). Task performance was compared with the questionnaire variables using correlation and regression analysis. Differences between the beginning and end of each shift were matched and compared using a paired Students t test.

RESULTS

SYNWIN performance was significantly worse at the end of a shift compared with the beginning of the shift (p = 0.028) primarily because of decrement in the memory component. The SYNWIN composite scores were negatively correlated to degree of irritability felt by the participant, both before (r = -0.25) and after (r = -0.34) a shift and were significantly correlated with amount of sleep (0.22), rest (0.30), and life satisfaction (0.30).

CONCLUSIONS

Performance by FCMs on a simple, rapid, computer-based psychological test correlates well with self-reported sleep, rest, life satisfaction, and irritability. Although further studies are warranted, these findings suggest that assessment of the performance of FCMs on a simple, rapid, computer-based, multitasking battery is feasible as an approach to determine their readiness to perform critical safety tasks through the SYNWIN task battery.

Feature absence-presence and two theories of lapses of sustained attention

We conducted two experiments using search asymmetry to test two theories of sustained attention lapses currently debated in the literature: the mindlessness theory and the resource theory. In the first experiment, participants performed a feature present and a feature absent sustained attention to response task (SART). The mindlessness theory predicts more commission errors in a feature present SART than a feature absent SART, while resource theory predicts the reverse, i.e. more commission errors in a feature absent SART than feature present SART. The latter occurred. In the second study, participants performed a naturalistic scene vigilance task with targets more analogous to a feature present search or more analogous to a feature absent search. The vigilance decrement occurred, with an increase in reaction time to targets over the course of the vigil. The decrement was more pronounced with the targets more analogous to a feature absent search. Overall, the results of both studies support a resource theory of sustained attention lapses, not the mindlessness theory.

A Multivariate Test Battery for Predicting Vigilance

It has proved difficult to predict individual differences in vigilance from standard psychometric tests. We report a study that explored the utility of a multivariate battery in predicting vigilance on a task requiring monitoring of a tactical display. A two-phase design was employed. Participants performed a short vigilance task (SVT) prior to the longer criterion monitoring task. We investigated the predictive ability of cognitive ability, personality, performance on the SVT, and stress responses to the SVT. Four versions of the criterion task were used, to test generalization of predictive validity. Key predictors of vigilance were found to include ability, SVT performance, and subjective task engagement and coping. Multiple regression analyses suggested that together these predictors explained about 30% of the variance in vigilance (with some differences for prediction of different task versions). Results are discussed in relation to the resource theory of vigilance, and the practical issues arising from selecting vigilant operators.